Apixaban (API) is a known compound having the following structure:

The chemical name of apixaban is 4,5,6,7-tetrahydro-1-(4-methoxyphenyl)-7-oxo-6-[4-(2-oxopiperdin-1-yl)phenyl-1H-pyrazolo [3,4-c]pyridine-3-carboxamide (CAS name) or 1-(4-methoxyphenyl)-7-oxo-6-[4-(2-oxopiperidin-1-yl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo [3,4-c]pyridine-3-carboxamide (IUPAC name).
Apixaban was disclosed in U.S. Pat. No. 6,967,208 and U.S. Patent applications Nos. 2012/0087978 and 2013/0045245, which are herein incorporated by reference in their entireties. Apixaban has utility as a blood coagulation factor Xa inhibitor, and is being developed for oral administration in a variety of indications that require the use of an antithrombotic agent, e.g., surgical operation of the hip or knee of the patient, and preventing death in atrial fibrillation, or using in the treatment of venous thrombosis.
At present, the common methods of improving drug stability and dissolution rate in the pharmaceutical formulation field include the followings: salifying, decreasing particle size, adopting non-aqueous solvent/cosolvent, preparing emulsion or self-microemulsion, inclusion with cyclodextrin, adopting thermodynamically unstable crystalline or preparing solid dispersions, and so on.
However, the pharmaceutical components of apixaban formulations and a preparation method thereof remain to be further studied.